(Photo: REUTERS / Stringer)United Nations (U.N.) High Commissioner for Refugees (UNHCR) Antonio Guterres (2nd L) sits with a family who fled from the violence in Mosul at the Khazer refugee camp on the outskirts of the Kurdish city of Arbil, July 17, 2014. Guterres said that a political solution was crucial to end the suffering of hundreds of thousands of Iraqi refugees who have been forced to flee their homes after the fall of their cities to Islamic militants last month.

Chaldean Christians are fleeing the northern Iraq city of Mosul as the world expresses outrage at the violent Islamist Islamic State of Iraq and the Levant's order that they either convert, leave the country or be executed.

The United States issued a strong condemnation of the systematic persecution of ethnic and religious minorities by ISIL which I trying to impose an Islamic caliphate in the region.

"We are outraged by ISIL's recent announcement that Christians in Mosul must either convert, pay a tax, leave, or face execution in the coming days," State Department spokesperson Jen Psaki told journalists Friday.

"We have also seen photos of reportedly Christian houses in Mosul marked with pejorative terms for Christians, as well as reports that Shia and Shabak houses have been similarly marked.

"ISIL also continues to target Sunni clerics and tribal sheikhs who disagree with its dark vision for Iraq," she said.

Human Rights Watch said Saturday that ISIS as ISIL is also known, "is killing, kidnapping, and threatening religious and ethnic minorities in and around Mosul."

Since capturing Mosul on June 10 the armed Sunni extremist group has seized at least 200 Turkmen, Shabaks, and Yazidis, killed at least 11 of them, and ordered all Christians to convert to Islam, pay "tribute" money, or leave Mosul by July 19, HRW said.

CHALDEAN PATRIARCH

Chaldean Patriarch Mar Raphael I Louis Sako described the dire situation Mosul, the second largest city in Iraq, as "tragic" since ISIL began driving Christians away, he told Asianews.it.

"For the first time in the history of Iraq, Mosul is now empty of Christians," said Chaldean Catholic Church leader Sako.

Christians are now thought to make up little more than 5 percent of Iraq's population of some 23 million people, The Wall Street Journal reported Friday.

Iraq once had one of the more vibrant Christian populations in the Middle East, but 10 years of war and the rise of Islamic extremism prompted many of them to emigrate.

"Christians either convert to Islam or pay the [poll] tax," the Patriarch Sako said, citing a notice being distributed by the militia in Mosul.

He noted that Christians can also leave the city but they could not take with them their possessions because the militia is seizing them.

ISIL has wrested control of Mosul from Iraq's central government, and the group established what it called an Islamic caliphate there.

The Iraqi government has launched a counteroffensive but it has been unsuccessful.

The patriarch, who has sought refuge at the See of the Chaldean Patriarchate in Baghdad, said it is impossible to request a dialogue with the militants.

The Islamists say their demands for Christians to leave are non-negotiable.

The church official has appealed to Christians to leave and seek refuge elsewhere. But he said the people behind there were the poor.

"Very few people, the poorest among the Christians are left because they do not have the means to escape," the patriarch said. The Christian refugees "are welcome in the monasteries, in the villages."

"Cars equipped with loudspeakers are driving through the city, telling Christians to flee," he continued. "At checkpoints, militias are seizing cars, money and papers from Christians, before letting them go . . . with nothing."

The patriarch attempted to engage members of the militia to talk, but he said even the central government did not have contact with the militants.

"There is no authority to deal with, no one," he said. "We do not know where they came from, what they really want. . . . The central government has no contact and now has started air strikes."

The U.N. mission to Iraq said Friday at least 5,576 civilians were killed and another 11,665 wounded in Iraq from January 1 until the end of June. In addition violence had forced 1.2 million people from their homes.

The report notes that in June, at least 1,531 civilians were killed in Iraq and 1,763 were wounded.